[INLONG-10644][Sort] Add the elasticsearch-base module to implement elasticsearch connector 6&7

[XiaoYou201]

[INLONG-10644][Sort] Add the elasticsearch-base module to implement elasticsearch connector 6&7

Fixes #10644

Motivation

Add the elasticsearch-base module to implement elasticsearch connector 6&7

To easy to develop

Modifications

Add some public constants, methods, classes, interfaces, etc.

[EMsnap]

Please add test result on es 6 or 7

[aloyszhang]

Plz add source information for es connector classes

[XiaoYou201]

Plz add source information for es connector classes

The es connector 6/7 are base on it. So,in my opinion, it is also a part of es connector.

[XiaoYou201]

Please add test result on es 6 or 7
As follow image, I implement es 6 connector and postgreSQL to ElasticSearch6 test successfully . But es6 base on this pr, so, the es6 connector pr will be submitted after this pr merged.

[aloyszhang]

BTW, Flink-1.15 needs this feature too, would you like to work on it?

[XiaoYou201]

BTW, Flink-1.15 needs this feature too, would you like to work on it?

yes, I would like to do that, it will done soon~